The advent of highly active antiretroviral therapy has resulted in a decline in the incidence of opportunistic infections and prolonged survival in HIV-1 infected individuals. Obstacles towards virus erradication include the continued presence of an infected quiescent pool, drug resistance, toxicities, and lack of treatment adherence. The goal of genetic therapies is the replacement of the HIV-1-infected cell reservoir with cells that have been genetically engineered to resist HIV-1 replication. Unlike conventional drugs, it is possible to create a "single administration" reagent. However, successful gene therapy strategies require efficient gene delivery into hematopoietic stem cells and the presence and expression of the anti HIV genes in differentiated progenies that persist for years if not for the life of the individual. Thus, these current limitations must be investigated. A better understanding of the limitations of gene therapy techniques can lead to strategies to overcome such limitations as well as design potential clinical scenarios in which to test them. As possible alternatives or complements to antiretroviral therapy, stem cell gene therapy strategies are of interest to the scientific community, to the health policy community in particular and to the public at large. The overall goal of the Gene and Cellular Therapy Core (Core G) is to provide scientific and technical support for basic laboratory and clinical trial projects that require the use of purified CD34+ hematopoietic stem cells for HIV/AIDS gene therapy, hematopoiesis and pathogenesis of HIV.